Alan, I really think your problem was with the wood. I once tried to chase a ring with the draw knife to make a bow from the lower half of a big hackberry stave. It was an exercise in futility. The thing chattered and before long I had speed bumps on the bow's back. Eventually I gave up and made firewood of my hackberry staves. A clear osage stave (which is almost an oxymoron) is wonderful to work with a draw knife. In fact, therein lies the danger. Just like with power tools, it is real easy to take wood off too fast and go through your ring. It's hard to argue with a 30 minute job on ring chasing though. I call ring chasing bowyers aerobics cause it always wears me out. At my age that's a good thing, I need all the exercise I can get.
Do you have osage over in the UK?
George